Phase-delayed laser diode array allows ultrasonic guided wave mode selection and tuning

被引:21
|
作者
Karppinen, Pasi [1 ]
Salmi, Ari [1 ]
Moilanen, Petro [2 ]
Karppinen, Timo [1 ]
Zhao, Zuomin [3 ]
Myllyla, Risto [3 ]
Timonen, Jussi [2 ]
Haeggstrom, Edward [1 ]
机构
[1] Univ Helsinki, Div Mat Phys, Dept Phys, Elect Res Lab, FIN-00014 Uusimaa, Finland
[2] Univ Jyvaskyla, Jyvaskyla 40014, Finland
[3] Univ Oulu, Dept Elect Engn, Oulu, Finland
基金
芬兰科学院;
关键词
BAND SURFACE-WAVES; LAMB WAVES; NARROW-BAND; GENERATION; TRANSDUCERS;
D O I
10.1063/1.4801394
中图分类号
O59 [应用物理学];
学科分类号
摘要
Selecting and tuning modes are useful in ultrasonic guided wave non-destructive testing (NDT) since certain modes at various center frequencies are sensitive to specific types of defects. Ideally one should be able to select both the mode and the center frequency of the launched waves. We demonstrated that an affordable laser diode array can selectively launch either the S-0 or A(0) ultrasonic wave mode at a chosen center frequency into a polymer plate. A fiber-coupled diode array (4 elements) illuminated a 2mm thick acrylic plate. A predetermined time delay matching the selected mode and frequency was employed between the output of the elements. The generated ultrasound was detected by a 215 kHz piezo receiver. Our results imply that this array permits non-contacting guided wave ultrasonic NDT. The solution is small, affordable, and robust in comparison to conventional pulsed lasers. In addition, it does not require experienced operators. (C) 2013 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4801394]
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页数:5
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